GB2346181A

GB2346181A - A belows member incorporating an elongate resilient member

Info

Publication number: GB2346181A
Application number: GB9901699A
Authority: GB
Inventors: Timothy Michael Cogger
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-01-27
Filing date: 1999-01-27
Publication date: 2000-08-02
Anticipated expiration: 2019-01-27
Also published as: GB2346181B; GB9901699D0

Abstract

A bellows member which is resilient to ballooning comprises a bellows (1) in the form of a plurality of elongate strips (3) interconnected along adjoining longitudinal edges (5) so as to permit relative pivoting movement between adjoining strips. An aperture is provided through the bellows and an elongate resilient member (7) passes through the aperture. The elongate resilient member (7) is secured at each side of the bellows, by a retaining element (9).

Description

BELLOWS MEMBER This invention relates to a bellows member.

Bellows members are well known for example for covering mechanisms that extend and retract. However, as the extent of movement of the mechanist to be covered, and hence the size of the bellows member, increases it has been found the bellows member is increasingly prone to ballooning (or bellowing out). One means of tackling this problem is to make the material of the bellows, and therefore the bellows member itself, more rigid, but this is not altogether satisfactory and in any event generally means the thickness of the bellows material must be increased leading to increased costs.

The present invention is therefore directed to a bellows member which is able to resist ballooning or bellowing out of the bellows member without the need for increased thickness of the bellows material.

According to the present invention there is provided a bellows member comprising: a bellows comprising a plurality of elongate strips interconnected along adjoining longitudinal edges thereof so as to permit relative pivoting movement between adjoining strips; an aperture provided through the bellows; an elongate resilient member passing through the aperture; and means for securing the elongate resilient member at each side of the bellows.

The resilient member may be made of rubber or other elastomeric material. The resilient member may be provided with a protective coating. Alternatively, the resilient member could comprise an inextensible portion and an extensible portion.

The securing means may comprise a retaining member having an aperture therethrough for the passage of the resilient member and a peripheral recess for retaining the resilient member therein. The peripheral recess may have a width, at least in part, less than the cross-sectional dimension of the resilient member. The peripheral recess may be tapered in the axial direction.

For a better understanding of the present invention and to show more clearly how it may be carried into effect reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 is a side elevational view of one embodiment of a bellows member according tp the present invention, the bellows member being in a retracted configuration; Figure 2 is a side elevational view of the bellows member of Figure 1 in an extended configuration; Figure 3 is a plan view of one embodiment of a retaining element forming part of the bellows member of Figures 1 and 2; Figure 4 is a plan view of another embodiment of a retaining element forming part of the bellows member of Figures 1 and 2; Figure 5 is a plan view of a further embodiment of a retaining element forming part of the bellows member of Figures 1 and 2; and Figure 6 is a side elevational view of the retaining element shown in Figure 5.

Figures 1 and 2 show a bellqws member 1 which comprises a plurality of elongate strips 3 of material interconnected along adjoining longitudinal edges 5 thereof in a manner such as to permit relative pivoting movement between adjoining strips 3 along the joint therebetween. Thus the bellows member 1 can move between a retracted configuration as shown in Figure 1 and an extended configuration as shown in Figure 2 simply by moving the remote edges of the bellows member apart or together.

The bellows member 1 is prevented from ballooning or bellowing out by providing a plurality of aligned holes through the strips 3 so as to form an aperture through the bellows member from one edge (or end strip) to the opposed edge (or other end strip) and by passing an elongate resilient member 7 through the aperture.

The resilient member 7 may be made of rubber or other elastomeric material which may be provided with a protective, for example abrasion resistant, coating if desired. The diameter of the resilient member will depend upon the particular requirements of each application and can readily be determined by simple experiments. However, I have found a diameter of about 5 mm to be generally satisfactory.

The resilient member 7 is secured in position at each edge with the aid of a retaining element 9 which facilitates retention of the resilient member 7 in the retaining element 9 while permitting ready adjustment of the length of the resilient member between the two retaining elements.

Various embodiments of the retaining element are more clearly shown in Figures 3 to 6.

To this end the retaining element shown in Figure 3 comprises a generally oval member provided with an aperture 11 adapted to allow passage of the resilient member 7 therethrough with relatively small clearance and a peripheral recess 13 having 4 radial depth greater than the diameter of the resilient member and a width, at least in part, less than the normal diameter of the resilient member but which is nevertheless able to receive the resilient member therein due to the resilience thereof.

Thus in Figure 3 the width of the peripheral recess 13 is substantially entirely less than the normal diameter of the resilient member, that is in both the radial and axial directions. In Figure 4 the peripheral recess 13 is generally triangular and is therefore less wide than the normal diameter of the resilient member primarily in the region of the apex. In Figures 5 and 6 the peripheral recess 13 is of substantially constant width in the radial direction, but is tapered in the axial direction so as to be less than the normal diameter of the resilient member in the region of one face of the retaining element.

The retaining element 9 in Figures 4 to 6 is generally circular rather than oval.

In use the resilient member 7 is assembled through the aperture in the bellows member 1 such that the ends of the resilient member extend beyond the bellows member at the opposing edges thereof. The retaining element 9 is then threaded onto the resilient member 7 such that the resilient member passes through the aperture 11 and the resilient member is bent over to run along a surface of the retaining element 9 and inserted into the peripheral recess 13 so as to pass through the retaining element once again.

Because at least a part of the peripheral recess is less wide than the normal diameter of the resilient member 7 the resilient member is retained in position due to friction against the walls of the peripheral recess. Friction between the resilient member and the surface of the retaining element and between the resilient member and the walls of the aperture 11 through the retaining element can further assist in retaining the resilient member in position.

I have found the resilient member can be securely retained in the retaining elements while permitting effectively infinite adjustment of the length of the resilient member between the two retaining elements according to need. The presence of the resilient member through the bellows member provides sufficient support to prevent the bellows member ballooning or bellowing out during use. Moreover, I have found it is generally not necessary to employ relatively thick material for the bellows member as has previously been necessary to achieve sufficient rigidity. Of course, more than one resilient member may be arranged along the bellows member if this is found to be desirable or necessary.

Claims

CLAIMS 1. A bellows member comprising: a bellows comprising a plurality of elongate strips interconnected along adjoining longitudinal edges thereof so as to permit relative pivoting movement between adjoining strips; an aperture provided through the bellows; an elongate resilient member passing through the aperture; and means for securing the elongate resilient member at each side of the bellows.
2. A bellows member as claimed in claim 1, wherein the resilient member is made of elastomeric material.
3. A bellows member as claimed in claim 2, wherein the resilient member is made of rubber.
4. A bellows member as claimed in any preceding claim, wherein the resilient member is provided with a protective coating.
5. A bellows member as claimed in any one of claims 1 to 3, wherein the resilient member comprises an inextensible portion and an extensible portion.
6. A bellows member as claimed in any preceding claim, wherein the securing means comprises a retaining member having an aperture therethrough for the passage of the resilient member and a peripheral recess for retaining the resilient member therein.
7. A bellows member as claimed in claim 6, wherein the peripheral recess has a width, at least in part, less than the cross-sectional dimension of the resilient member.
8. A bellows member as claimed in claim 6 or 7, wherein the peripheral recess is tapered in the axial direction.
9. A bellows member substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.